Tanning injections come in two forms: melanotan I and melanotan II. Both types of injections work by replicating alpha-melanocyte-stimulating hormone in your body. This hormone binds to melanocortin receptors and stimulates the production of the pigment melanin in your skin cells. The more melanin your skin cells produce, the darker your skin appears.

Melanotan I lasts longer in your body than melanotan II before being broken down by enzymes. Melanotan I is known as afamelanotide when used medically.

Afamelanotide is sold under the brand name Scenesse, and it’s used to prevent phototoxicity in people with a condition called erythropoietic protoporphyria. People with this rare genetic disorder experience severe pain when their skin is exposed to sunlight and some artificial lights.

Melanotan II binds with a wider range of receptors than melanotan I and has a shorter life in your body. It can also cross your blood-brain barrier, which can cause side effects like appetite loss, sexual dysfunction, and fatigue. Melanotan II is not currently used to treat any medical conditions.

Both melanotan I and melanotan II are unregulated and often sold illegally online. Online retailers aren’t monitored by any governing health organization, so there’s a high risk that products have been mislabeled or contain impurities. One small 2015 study found that melanotan II bought from two different vendors contained between 4.1 to 5.9 percent impurities.

One of the biggest concerns around tanning injections is that they’re unregulated. Without proper regulation, there’s no guarantee that the product you’re using has been properly labeled. Plus, the long-term effects of using melanotan I and melanotan II remain largely unknown.

In one observational survey, researchers questioned 21 volunteers who had used melanotan in the past, were actively using it at the time of the survey, or were considering using it in the future. The researchers found that the most common side effects were:

• nausea
• flushing
• loss of appetite
• drowsiness

In the 1980s, one of the researchers involved in the development of melanotan II self-described himself as a “human guinea pig” when he injected himself with it. After accidentally injecting double the intended dose, he experienced an 8-hour erection, nausea, and vomiting.

Melanotan use has been linked to the following conditions. More research is needed, though, before researchers can definitively say that melanotan causes these conditions.

Erectile dysfunction

A 2019 case study describes a man who experienced acute priapism after injecting himself with melanotan. Priapism is a prolonged and painful erection caused by excessive blood flow. The man was admitted to the hospital but didn’t require surgery. At a 4-week follow-up, he still hadn’t recovered erectile function.

Skin cancer

More research needs to be done before scientists can confirm whether melanotan increases your risk of developing skin cancer. Still, this remains one of the biggest concerns around the use of tanning injections.

According to a 2017 review, there are at least four case reports of melanoma emerging from moles after the use of melanotan. There’s also some evidence that melanotan use is linked to the emergence of new moles.

In one of the case studies, a 20-year-old woman was referred to a dermatology clinic after developing a jet-black mark over her glute that was later diagnosed as melanoma. She had been injecting melanotan II every other day for 3 to 4 weeks.

Kidney failure

According to a 2020 review, melanotan II has been linked to a potentially life threatening condition called renal infarction. Renal infarction develops when blood flow to your kidneys is blocked. It has a mortality rate of about 11.4 percent within the first month of diagnosis.

Injection risks

Tanning injections come with the same risks as other forms of injections if they’re not properly prepared, such as:

• hepatitis B and C
• HIV/AIDS
• nerve damage
• abscess
• septicemia (blood infection)

Melanotan I and melanotan II are illegal to purchase in the United States and the United Kingdom. Despite this, they are still widely sold on the internet or at health clubs and gyms.

Afamelanotide is an orphan drug approved by the Food and Drug Administration. It’s used for the treatment of the rare genetic disorder erythropoietic protoporphyria.

All melanin injections are unsafe when used for the purpose of changing skin color. Melanin injections are unregulated and have the potential to cause life threatening side effects. Illegally purchased injections bought online may be mislabeled or contain impurities that could be seriously harmful to your health.

Tanned skin is considered attractive in many Western cultures. But most methods of darkening your skin increase your risk of skin cancer and offer no health benefits.

Tanning injections darken your skin by replicating a hormone in your body that stimulates the production of melanin in your skin. All forms of tanning injections are currently illegal to purchase in the United States.

Tanning injections aren’t regulated, and there’s little research on their long-term effects. Some research suggests that they may increase your risk of developing skin cancer.